Type bar mechanism for typewriters



July 8, 1941. A, TOMYBOLINI 2,248,691

TYPE BAR MECHANISM FOR TYPEWRITERS J Original Filed July 8, 1935 mm;fink/121i Patented July.8, 1941 UN TED-STATE ms m MECHANISM son.mnwmrnns Alfredo Tombolini, Milan, Italy,

. collimat on jot application Serial No. sass-1. my 8, 1935. Thisapplication August 2, 1939, Serial No. zsaoss 'iclsim, (br m--22) Thisinvention relates to an improved type bar mechanism for typewriters andhas'for its object pivot 2 fixed to the frame of the typewriten'and,

the provision or a mechanism oi this character by the use of which thewhole type .bar set, together with the supporting segment and part ofthe intermediary levers may be downwardly shifted by depression-oi thecapital. letter key, thus eliminating the necessity for raising-oi thecarriage for writing the capital letters. 7

To permit downward shifting of the whole set-v of type bars togetherwith their supporting segment and partof their actuating levers, a newkinematic mechanism is necessary. This mechanism not only must allowthevertical shitting,

but must also permit the actuation oi the type bars by means of the keybars through inter-- mediary levers,- in both the normal and loweredposition 01 the set.

There are-known mechanisms for the purpose oi vertically shitting thetype bar set for writing capital'letters. All ,0! these knownmechanisms,

' however, involve more or less considerable inconveniences, becausethey are too, complicated,

Each key bar I is adapted to about a carries a pin 3 to which one arm01' a lever 4 is connected. Each of. the cranked levers,

I is adapted to swing at 5 about astraight pivot, fixed to the frame ofthe machine and its other arm isconnected to a strip [the opposite endof which is hinged to a shapeddever I. Lever I isadapted to swing at sabouta straisht brid e 14 common to-all oi the levers "I and beingadapted to be vertically loweredby depretsion f of. capital letterkeys-connected at the lateral ends thereof. .The upper .end oi lever Icarries v a pin 9 by means of which said lever I engages I ;a slot l0 0!the type'bar II; the type bar ll--isadapted to'swing at It about thesegment pivot 3, the vertical.

common to all type bars.

As willbe clearly seen in Figure I arms of cranked levers s are all 0!the same length, while the horiz'ontal'arms oi said'levers becomeprogressively longer from the center of or so different from thevenistingnormal-mechanisms as to require a considerable transformationof the typewriter itself, or. else because they require special typebars and 'do not allow for the use of normal type bars ofthe kind nowem- 1 ployed by the most important manufacturers all over the world."Their use isturther disadvantaweous in that they do notialiow exchangeof the type bars individually. because they requireia secondsemicircularsegm'ent underlyingthe sup 1 porting segment of thetypebars, and-because th Present-other constructional or functional defi allQthe aforesaid inconveniences at the same time assures equallygoodfunction in both pullingratherthanpushing action.

In the accompenvins drawing: Figure ishowsatypebarconnectedtothe corrponding key bar with the intermediary levers; the broken lines show thelowered position oi-the elements which become ioweredbydepression or thecapital IetWkOYS,

the'set toward-the sides.- Consequently the distance between points Iand I progressively increases irom the center towards the sides. This isnecessary to compensate for the diii'erent leverage between elements 8and I. as the actuating levers I become also progressively longer i'rom'the center of the set towards'tbe sides to follow the'semicircularsupporting segment of the type Besides the m siive increase in -thelength oihorizontai arms'oi levers 4 towards the sides, said horizontalarms have further diilerent lengths in accordance with the key'bars towhich. they are connected, because there are iourgroups 35 oihey barshavins diilerent lengths.

s all-havethesaineshape on tiresome-level and are hinged to levers I.

"I and causes it to swingin forward direction about'the pivot I; thetypebar "is thusswung' about its pivot i2 and roller oi the carriage. asshown with dotted lines in Asshowninl 'igzlaportionoithemechanismmaybelowered.namelythewholesetoitypebars All togetherwiththeirsupportingpivot ,astuating levers l.strips iandbridge a, ll.

mireieorresponmtol lg. Lbut the mam urp se-t cm as: 'segmentisapproximately individually detaebably 3 w v When a key I is depressed,the lever l isactuthe normal and lowered position of the type bar 9 atedand by means '0! strip"! actuates the lever set. Furthermore, "theleverage oi the kinematic system is most favourable, all elements havingPorthis.

sguided inthetrameoithemachlneandtheumal capitallettersareoonnectedtothe ends of bridge JIIoastJoIeritIhentheybecomedepresIed. "rhenormalpolition'isrestoredbymeansoione mrm fimlmm the strikin: position oi thebet-bar: m e I- I l v I 3 is'a perspective view which shows'one hail ofthe mechanism formed according ,tothe In the mechanism described above,all parts work edgewise i'with pulling action. The consequence isthat""the keyboard is extraordinarily rigid (not springy).

A further feature of this mechanism lies in the simplicity oimanufacture. For instance the angle-levers 4 and strips 8 may bemanufactured all alike in shape and dimensions; the former may be easilyshortened afterwards to give them the required lengths.

This application is a continuation of application Serial'Number 30,387,filed July 8, 1935.

What I claim is: y

In a typewriting machine, a frame, key bars pivoted ,on a common axis insaid frame and having keys arranged thereon in different rows,

a type bar supporting segment mounted for.

downward case shifting movement on said frame, type bars pivoted on saidsegment, a straight bridge connected to said segment for downward 20connected to said key bars at difierent distances from said fixedstraight." pivot according to the different key rows and according tothe different leverage of said actuating levers, said straight bridgeand actuating levers being arranged behind the bell crank levers, andthe key bars being downwardly offset to accommodate said straight bridgeand fixed straight pivot and to allow downward shifting of said straightbridge.

' ALFREDO TOMBOLINI.

